I'm a little late to the table here, in that I've only just gotten around to playing ToMI (why did I wait?) and I really loved it. I was of the opinion that adventure gaming was well and truly dead, and felt like I hadn't played a good one since Grim Fandango a bajillion years ago. But ToMI really worked. The last chapter in particular was spectacularly good.
But the thing I noticed about the last chapter was also that it looked much better than the other chapters. The reason for this was the lighting of the underworld - it made everything seem as if it had dark outlines, giving it a much more cartoony vibe.
So I'd like to make a suggestion. If we ever do get a second season of ToMI (and I really hope we do), it'd be really great if black outlines were added to everybody - much like in the short-lived (and not really to my taste, gameplay-wise) Penny-Arcade games. It makes the stylised, cartoony graphics look so much more stylised and cartoony (and I'm a big fan of stylisation over realism).